1. Field
The present disclosure is directed to a method and apparatus for ascertaining a location of a personal portable wireless communication device. More particularly, the present disclosure is directed to ascertaining a location of a personal portable wireless communication device based on sensed movement of the device and measured wireless network signal strengths.
2. Introduction
Presently, some wireless communication devices can determine their locations based on signals received at the devices. For example, a wireless communication device can determine its location based on Global Positioning System (GPS) signals, cellular signals, or other signals. The location can be used to find directions on a map, to locate a device user during an emergency, to provide social networking updates, to tag photographs with the location, to locate points of interest proximal to the device, and for other location purposes.
Unfortunately, the location is subject to errors that result in the determination of an inaccurate location. For example, GPS location determination techniques suffer from accuracy problems and are subject to problems when GPS signals cannot be received, such as when the device is indoors, underground, or among tall buildings. Furthermore, cell tower location triangulation determination techniques suffer from similar and other errors. Other location determination techniques, such as wireless local area network location determination and dead reckoning location determination techniques, also suffer from similar and other errors, such as errors caused by reflective surfaces, multipath issues, dead-spot issues, noise issues, interference issues, sensor inaccuracy issues, and other issues. These errors make it difficult to accurately determine the location of a device.
Thus, there is a need for a method and apparatus for ascertaining a location of a personal portable wireless communication device.